FDA Pauses Trials of Gilead HIV Combination After Safety Signal

Gilead Sciences Inc. said federal regulators had placed on hold trials of a new experimental once-weekly HIV drug combination therapy after white blood cell counts dropped in some of the patients.

The studies were testing two experimental HIV drugs, GS-1720 and GS-4182, when given together. Gilead said the Food and Drug Administration paused the trials due to a “safety signal” triggered by a decrease in lymphocyte levels in some patients given the therapy. Lymphocytes are a type of white blood cell that play a critical role in the immune system’s ability to fight infections.

Gilead shares declined as ...